Influence of femoral tunnel exit on the 3D graft bending angle in anterior cruciate ligament reconstruction

Journal of Experimental Orthopaedics

Sylvano Mania¹  Lazaros Vlachopoulos¹  Sandro F. Fucentese¹  Sandro Hodel¹  Philipp Fürnstahl² 

[1] Department of Orthopedics, University of Zurich, Balgrist University Hospital, Forchstrasse 340, 8008, Zurich, Switzerland;Research in Orthopedic Computer Science (ROCS), University Hospital Balgrist, University of Zurich, Forchstrasse 340, 8008, Zurich, Switzerland;

关键词: ACL;    Anterior cruciate ligament;    Graft bending angle;    GBA;    Femoral tunnel;   

DOI  :  10.1186/s40634-021-00364-9

来源: Springer

【 摘 要 】

PurposeTo quantify the influence of the femoral tunnel exit (FTE) on the graft bending angle (GBA) and GBA-excursion throughout a full range of motion (ROM) in single-bundle anterior cruciate ligament (ACL) reconstruction.MethodsThree-dimensional (3D) surface models of five healthy knees were generated from a weight-bearing CT obtained throughout a full ROM (0, 30, 60, 90, 120°) and femoral and tibial ACL insertions were computed. The FTE was simulated for 16 predefined positions, referenced to the Blumensaat's line, for each patient throughout a full ROM (0, 30, 60, 90, 120°) resulting in a total of 400 simulations. 3D GBA was calculated between the 3D directional vector of the ACL and the femoral tunnel, while the intra-articular ACL insertions remained unchanged. For each simulation the 3D GBA, GBA-excursion, tunnel length and posterior tunnel blow-out were analysed.ResultsOverall, mean GBA decreased with increasing knee flexion for each FTE (p < 0.001). A more distal location of the FTE along the Blumensaat's line resulted in an increase of GBA and GBA-excursion of 8.5 ± 0.6° and 17.6 ± 1.1° /cm respectively (p < 0.001), while a more anterior location resulted in a change of GBA and GBA-excursion of -2.3 ± 0.6° /cm (+ 0.6 ± 0.4°/ cm from 0–60° flexion) and 9.8 ± 1.1 /cm respectively (p < 0.001).Mean tunnel length was 38.5 ± 5.2 mm (range 29.6–50.5). Posterior tunnel blow-out did not occur for any FTE.ConclusionAiming for a more proximal and posterior FTE, with respect to Blumensaat’s line, reliably reduces GBA and GBA-excursion, while preserving adequate tunnel length. This might aid to reduce excessive graft stress at the femoral tunnel aperture, decrease femoral tunnel widening and promote graft-healing.Level of EvidenceIV

【 授权许可】

CC BY